Extra bedroom and en-suite extensions in Castlederg
Homes in Castlederg with a bit of space to the side or rear can often take an extra bedroom and en-suite extension. We'll tell you honestly whether yours can, and what approvals it needs.
What we'd confirm first for a project in Castlederg.
- Postcode districts
- BT81
- County / area
- County Tyrone, Northern Ireland
- Price region
- Northern Ireland
- Guide price
- £49,500–£66,500 (£1,760–£2,380 per m²), plus £5,500–£11,000 for the en-suite
- Approval route
- It may be permitted development if it goes no more than 3 m beyond the original rear wall and stays 7 m from the rear boundary.
- Nearest towns
- Sion Mills (7.4 miles), Strabane (9.5 miles), Omagh (13.9 miles)
- Distance to Omagh
- about 13.9 miles
- First visit
- Free, no obligation
About an extra bedroom and en-suite extension
An extra bedroom and en-suite extension is a two-storey extension planned around a new double bedroom with its own shower room on the first floor, with a ground-floor room below. It is one of the most effective ways to add space for a growing family. Nationwide's 2025 research linked adding a double bedroom and bathroom to a three-bed, one-bathroom house with value gains of up to 24%.
We cover postcode district BT81 in and around Castlederg, along with neighbouring Sion Mills, Strabane and Omagh.
What it costs in Castlederg
Most of the cost of an extra bedroom and en-suite extension is set by its size and specification. For Castlederg and the rest of Northern Ireland, our guide is £1,760–£2,380 per m² including VAT, so about £49,500–£66,500 (plus £5,500–£11,000 for the en-suite) for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.
| Spec | Per m² | A 4 m × 3.5 m footprint on two floors (28 m² of new floor space) |
|---|---|---|
| Essential | £1,620–£2,190 per m² | £45,500–£61,000 |
| Standard | £1,760–£2,380 per m² | £49,500–£66,500 |
| Premium | £2,110–£2,850 per m² | £59,000–£80,000 |
Planning and building control in Castlederg
In Northern Ireland, a rear extra bedroom extension can be permitted development within 3 m of the original rear wall and 7 m from the rear boundary. Upper side windows within 15 m of a neighbouring boundary must be obscure-glazed and non-opening. Other designs need a planning application costing £347, plus building control approval.
Approval in Northern Ireland: Planning application for works to a house: £347. Councils aim to decide local applications within an average of 15 weeks; many take longer.
Building control: Building control approval from the local council under the Building Regulations (Northern Ireland), using the Technical Booklets.
Design points for Castlederg homes
Sound and privacy
Bedrooms above a kitchen or family room benefit from an insulated floor to reduce noise. Side-facing upstairs windows usually have to be obscure-glazed, so we place the main bedroom window to the rear and the en-suite window to the side where possible.
Escape window and fire safety
A new first-floor bedroom needs an escape window with a clear opening of at least 0.33 m², at least 450 mm wide and high, and the bottom no more than 1,100 mm above the floor, unless there is a protected route to the stairs. We design the windows to meet this.
How we'd run your project
Look at the house
We start in Castlederg with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Get it approved
Once you're happy with the design we submit it to the council for Castlederg and deal with any questions from the planning officer.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.
Questions about extra bedroom and en-suite extensions in Castlederg
Do I need planning permission for an extra bedroom and en-suite extension in Castlederg?
Castlederg is in Northern Ireland. It may be permitted development if it goes no more than 3 m beyond the original rear wall and stays 7 m from the rear boundary.
How much does an extra bedroom and en-suite extension cost in Castlederg?
Our guide for Northern Ireland, which covers Castlederg, is £1,760–£2,380 per m² including VAT. A typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £49,500–£66,500 (plus £5,500–£11,000 for the en-suite). Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Which postcodes do you cover around Castlederg?
We cover Castlederg (BT81) and nearby places including Sion Mills, Strabane and Omagh, plus the rest of County Tyrone. The first site visit is free.
Does an extra bedroom add value to my house?
It usually does, though not always by the full cost. Nationwide's 2025 research found that adding a double bedroom to a two-bed house was linked to about 13% higher value, and a double bedroom and bathroom on a three-bed, one-bathroom house up to 24%. Local ceiling prices still apply.
How big should a new double bedroom be?
There is no legal minimum size for a bedroom in a house you own, so the test is whether it works. A comfortable double needs room for the bed with space to walk round it, wardrobes and a door that opens freely. We draw furniture on the plans so you can judge the space before anything is built.
Nearby
Other towns near Castlederg:
Other extensions in Castlederg
All two-storey extension services in Castlederg · Extra bedroom and en-suite extensions across County Tyrone
Send us your postcode and a few details. We'll get back to you to arrange a visit and talk through your options.